During part 1 (the cut) you created a deficit in calories, that resulted in fat-loss. You've reached your goal, but you can't stay in a caloric deficit for the rest of your life. Also your maintanance level has dropped significantly, because after a certain period of dieting your body will adjust itself. This is where the reverse diet comes into play.

At this point in your diet you should know your exact intake, because you've been weighing all your food and tracking it with your app.

You're going to use this as a starting point and slowly up your intake again. I usually recommend to add 50-100 calories every week, consisting of carbs and fats. Your protein intake should always be around the same amount.

What your doing is teaching your body to burn more calories without adding any body fat. You can keep adding calories until you're at a point that you're comfortably hitting your daily targets without struggling. During your reverse diet it's even more important that you track everything.

After all of this is done you have a healthy appetite, you're able to have a cheat without feeling the need to start binging and you created the body that you're happy with.